Interannual variations and trends in remotely sensed PM2.5 along the Maritime Silk Road from 2000 to 2014

摘要

As the World Health Organization (WHO) has reported, air pollution both indoor and outdoor caused nearly 7 million deaths in 2012. Due to the rapid process urbanization and industrialization, air pollution in the form of fine particle matter continues to be a severe environmental problem in large cities in China. In particular, PM_2.5 refers to aerosol particles smaller than 2.5 μm in diameter that are suspended in the air. According to previous studies, human exposure to PM_2.5 can cause development of various respiratory and cardiopulmonary diseases. Thus, quantifying human exposure to PM_2.5 is necessary for public health risk assessment. Satellite remote sensing has proved to be a cost-effective tool for PM_2.5 concentration estimation. In our study, the ground-level fine particulate matter (PM_2.5) concentration dataset with a spatial resolution of 1 km was used to analyze spatial temporal variations of PM_2.5 concentration from 2000 to 2014 along the Maritime Silk Road. The inter-annual changing trends of PM_2.5 in 12 large urban agglomerations along the Maritime Silk Road were investigated in detail. The urban agglomerations including Dhaka, Kolkata and Mumbai have experienced the most rapid increase of PM_2.5 concentration with the average annual rates of 1.08 ug/m^{3, 1.44 ug/m3 and 0.79 ug/m3, respectively from 2000 to 2014. The areal extent of PM_2.5 concentration over 35 ug/m3 increased from 15.2% in 2000 to 64.5% in 2014 in the large urban agglomerations. These findings can provide useful information for reducing human risk to air pollution and promote sustainable urban development in China and countries along the Maritime Silk Road.}